According to editor Jerry Thompson, in his introduction to Tejanos in Gray: Civil War Letters of Captains Joseph Rafael de la Garza and Manuel Yturri, the de la Garza and Yturri letters are the most valuable set of existing writings by Texan Civil War soldiers of Hispanic descent. As he is perhaps the premier historian of the Civil War in the Southwest and the most prominent researcher of the approximately 4,000 Tejano Union and Confederate soldiers, Thompson's opinion carries significant weight.

While the experiences of enlisted men were lost to history through shoddy paperwork and widespread illiteracy, de la Garza and Yturri were bilingual, college educated, and from prominent Texas landowning families. Although their surviving letters do not specifically state why they attached themselves to the Confederate cause, Thompson surmises that family intermarriage with secession-sympathizing Anglos played a role. Yturri himself married de la Garza's older sister. Both men joined the second wave of Confederate recruiting, serving with the 6th Texas Infantry in the Western Sub-District of Texas. De la Garza later transferred to the 33rd Texas Cavalry before accepting a captaincy in the 3rd Texas Infantry. Neither saw sustained combat on the scale seen by those fighting in the eastern and western theaters, and both were absent for the 1863 Arkansas Post surrender. Nevertheless, de la Garza was killed in Louisiana during the April 8, 1864 Battle of Mansfield. Yturri survived the war, prospered, and lived well into old age.

Readers expecting to read extensive passages describing various skirmishes and battles won't find much. There are the usual camp, picket, and march details, but there is really one one battle piece. By Yturri, it relates what he saw of the 1864 Battle of Jenkins Ferry. However, it is apparent from the large gaps between dates that many letters are missing, so perhaps others existed at some time. Instead, the writings of both men are intensely family focused, inquiring after the health and doings of friends and relatives, and offering their wives financial and child rearing advice. A constant refrain, common to Civil War soldiers on all fronts, is the lament of not receiving return letters [these brothers-in-law appear to have been particularly afflicted, perhaps victims of a less than stellar Trans-Mississippi mail service].

As with his other edited works, Thompson's editorial and source notes accompanying the letters are of immense help in sorting out the many persons, places, and events mentioned in the text. The product of diligent research in manuscript repositories, service and other government records, church files, newspapers, books and articles, the endnotes are extensive (some a full page in length) and often make for fascinating reading in their own right. Given the high quality of Thompson's work and the fact that similarly themed publications are almost entirely absent from the literature, Tejanos in Gray is highly recommended reading for those interested in the Mexican-Texan contribution to the Confederate cause, as well as the Civil War in Texas in general.